The Loneliest Whale (the search for 52) recently added to Netflix:
Insights into the film and Cascadia’s role

Netflix recently added the acclaimed documentary The Loneliest Whale: The Search for 52 to its lineup in late October 2025. The film holds an impressive 88% rating on Rotten Tomatoes. Filmed in 2015, this 90-minute documentary was originally released in 2021 and brings attention to the challenges whales face in the North Pacific.

In the opening scene, long-term Cascadia Research Collective supporters will recognize the unmistakable iconic imagery of one of Cascadia’s RHIB’s – tagger posed in the pulpit with a long tagging pole in hand. The later half of the film exhibits John Calambokidis and James Fahlbusch skills as they tag multiple whales to document their calls and underwater behavior. Cascadia’s team has tagged hundreds of whales and spent thousands of hours working on the water, making them the perfect duo to join the epic quest to locate a mysterious whale known only by its unusual 52-hertz call.

The Story Behind the 52-Hertz Whale

The “52-hertz whale” was first detected in 1989 by researchers at the Naval Air Station Whidbey Island, using the U.S. Navy’s SOSUS underwater listening system. Its distinctive call was tracked intermittently until 2004 and studied extensively by Bill Watkins and his colleagues at the Woods Hole Oceanographic Institution (WHOI). Their 2004 publication, released the same year Watkins passed away, summarized 12 years of acoustic data.

Initially regarded as an obscure scientific curiosity, the 52-hertz call took on a life of its own after being dubbed “The Loneliest Whale.” The idea of a whale calling into the vast ocean in a voice no other whale could understand resonated deeply with people around the world.

Although the Navy no longer monitors this call, researchers at Scripps Institution of Oceanography have since detected similar calls – suggesting that there may be more than one “52-hertz whale” out there. Although these similar calls are slightly lower in pitch, scientists have observed a global trend amongst blue whales of lowering the pitch of their calls as well.

Cascadia’s Role in the Expedition

The film captures only part of a larger scientific story. John Calambokidis and Cascadia Research Collective played key roles in the expedition depicted in The Loneliest Whale: The Search for 52, contributing both expertise and field operations.

Much of the film’s production was made possible through a Kickstarter campaign that raised over $405,000 from more than 3,000 supporters, of which Cascadia received modest funding to help launch the 2015 expedition featured in the film. Initially conceived as a pilot effort to refine field methods for a larger planned voyage, the broader expedition never took place—largely due to challenges securing a more capable research vessel. Nonetheless, the team’s work at sea achieved several important objectives for the study of whale acoustics and tested new tagging and tracking techniques, which have benefited the study of many whales species.

Although the team did not locate the 52-hertz whale during that mission, a hybrid whale remains one of the most likely candidates for the animal producing the 52-hertz call. The hybrid whale discussed in the film, CRC-BM-3330/CRC-BP-114, was first documented in 1995.

The map shows the track of the hybrid whale while it was tagged in 2015 by Oregon State University. It was during that time period, which was discussed in the film, that an attempt was made to determine whether the 52-hertz call was captured on Scripps Institution of Oceanography recording stations during a period when this hybrid whale was known to be nearby, but the results were inconclusive. Cascadia continues to document and track this individual, and findings are summarized in a 2021 scientific publication: Jefferson et al. 2021, Aquatic Mammals.

Panel a) Map of the 20 sighting location of the blue/fin whale hybrid between 1995-2020. Panel b) Tracks of the blue/fin hybrid in 2015 while it was tagged for 28.1 days off California (Jefferson et al. 2021, Aquatic Mammals).

The film cryptically ends with footage John took a year later during one of Cascadia’s research surveys in Southern California. John observed the hybrid whale feeding among 15–25 blue whales and even closely paired with another blue whale. These observations suggest that if indeed the hybrid is the “52-hertz whale” despite producing an unusual call it is not necessarily isolated from other whales. A poignant reminder that “loneliness,” in this case, may be more myth than fact.

Below is a comparison among the blue/fin whale hybrid and two blue whales. The hybrid (the right side shown) has a larger dorsal fin and faint mottling. The two blue whales (left sides showing) exhibit both lighter and darker pigmentation patterns.

A Recent Connection

In January 2025, John Calambokidis gave a presentation on blue whales for Orca Network’s Ways of the Whales event. The talk referenced the 52-hertz whale and John was pleasantly surprise to discover one attendee was Joe George, the retired U.S. Navy acoustician who first detected the call in 1989! The two had the rare opportunity to compare notes and share insights more than 35 years after that first mysterious call was recorded.

Images taken under and research & response activities conducted under NOAA permit #’s 16111, 18786, 21678, 24359, and 28850.